Groin herniorrhaphy is among the oldest and most common surgical procedures performed. Unfortunately, the average operative result is beset by a period of discomfort with resultant disability. Techniques have been developed, such as laparoscopic herniorrhaphy, with the intent to reduce morbidity and recurrence rates. Most trials, however, have noted only a moderate improvement in the pain and disability associated with the procedure. Further, the added cost of equipment, the need for general anesthesia, and the additional operating room time required for this procedure indicates that it is less than ideal. There continues to be a need in general surgery for a procedure that can effectively address all the considerations of cost, disability, and hernia recurrence for patients with an inguinal hernia.
Failure of the transversalis fascia to retain the peritoneum from penetrating the myopectineal orifice is the fundamental cause of all groin hernias. Historically, hernias were repaired by stretching the transversus abdominis tendon across the myopectineal orifice and suturing it to the inguinal ligament. This technique and its current modifications rely upon the surgical approximations of edges of the defect to cover the myopectineal orifice. Such a technique, however, results in a distortion of the groin anatomy which creates stress on both the suture upon which the hernia repair is dependent and on the tissue planes that have already demonstrated their inherent weakness by the presence of a hernia. It is believed that the tension placed on the suture line as a result of the unnatural approximation of the tissues leads to recurrence, especially early recurrence.
A relatively modern technique to effect hernia repair is to place a prosthetic mesh over the myopectineal orifice. This technique enlists the intra-abdominal pressure to secure the inlayed prosthesis to the pelvic floor rather than allowing it to act as a factor in recurrence of the hernia. After mesh placement, the peritoneum becomes nondistensible, so there is no need for hernia defect closure. An effective modification of this technique is to place a polypropylene mesh on the outside of the myopectineal orifice. The prosthesis is sutured to the adjacent tissues with a minimum of tension. This repair has proven effective in preventing both short- and long-term recurrence. In addition, the pain associated with this operation is less than with other open operations. Its single disadvantage is the required division of tissue to gain access. The operation is commonly performed under local anesthesia with sedation. Hospitalization is avoided and most patients return to work as rapidly as those experiencing the laparoscopic preperitoneal herniorrhaphy.
Several mechanisms of hernia recurrence have been identified, such as the use of an inadequately-sized prosthesis so that the entire myopectineal orifice is not covered. Related to this concept of an inadequately-sized mesh is the possibility of inadequate overlap. It is felt that all defects should be overlapped by at least 2 cm if the mesh is stapled and by 3 cm or more if not stapled. For example, the myopectineal orifice measures approximately 10 cm.times.8 cm in an adult so a 16 cm.times.14 cm mesh is required.
While the placement of a prosthetic mesh in the preperitoneal space is currently performed with either a laparoscopic or an open technique, it is desirable to perform the procedure by placing small needle cannulas in the groin to dissect the preperitoneal space. Visualization would be obtained with a 2 mm laparoscope placed through one of the cannulas. The hernia sac would be dissected free and ligated. A prosthetic mesh would thereafter be placed to reinforce the transversalis fascia The patient would have reduced pain and disability as currently is associated with the procedure. In addition, the need for general anesthesia could be eliminated.
Such a needle herniorrhaphy technique requires a device for creating an operating space in registry with the myopectineal orifice. The device should be insertable through the cannulus of a needle. The device should further be either retrievable through the cannulus of the needle after creating the operating space or biodegradable so that it may be left in place over the herniated region.
Such a needle herniorrhaphy technique also requires a prosthesis employing a thin surgical support mesh that may be rolled or folded and thereafter inserted within the cannulus of a needle. The mesh should also be non-linting, fray resistant, and ravel resistant The mesh must be sufficiently porous to allow for tissue growth through the graft after implantation. The healing tissue grows through porous openings in the implanted mesh, thereby assimilating the mesh and adding structural integrity to the tissue.
The mesh is desirably self-opening upon emplacement over the myopectineal orifice. The mechanism for self-opening for the prosthesis must be reliable and should further provide suitable rigidity to the prosthesis in an open configuration, without unduly interfering with the anatomical members in the vicinity of the myopectineal orifice. Specifically, while the prosthesis should provide support to each side of the myopectineal orifice, the prosthesis should not interfere with, and risk closing of, the vas deferens. Additionally, the prosthesis should pose no risk of puncturing the peritoneurm so as to induce infection.